This invention relates in general to an adapter for attachment to a jack used to raise the front end of a vehicle when making wheel alignments. The adapter permits the vehicle to be jacked up and held in a safe position when compared with raising the front end of the vehicle without the adapter.
Automobile mechanics typically perform front end alignments by initially positioning the automobile on a wheel alignment rack. Although wheel alignment racks can vary, they commonly include a pair of spaced apart, parallel runways onto which the automobile is driven. The front wheels of the automobile rest on turntables at the front ends of the runways. The wheels can be steered clockwise or counterclockwise through a given angle in preparation for measuring the toe-in and caster angles of each wheel. The camber setting for each wheel is made by jacking up each wheel above the turntable and then making the necessary camber adjustments to the front end suspension system.
In jacking up the automobile, the jack is typically placed under the front steering control arm of the front suspension system. Wheel alignment racks commonly are equipped with wide pads spaced inside the turntables for supporting a jack below each control arm. The ram of the jack is forced vertically against the bottom of the steering control arm to raise the front end of the automobile. The jack is held in its raised position against the bottom of the steering control arm while the mechanic makes the necessary adjustments to the camber setting.
This is not an entirely safe procedure for making wheel alignments. This is primarily due to the configuration of most steering control arms. The undersurface of the steering control arm immediately adjacent the wheel extends for a short distance in a relatively horizontal direction, but the undersurface of the steering control arm then angles upwardly away from the wheel. When raising the front end, the ram of the jack is commonly forced upward against this angled portion of the steering control arm. This contact is at a dangerous angle that does not provide a stable means of holding the front end of the automobile in its elevated position. There have been many instances where the automobile has either slipped sideways off of the jack, or the automobile has slid entirely off the alignment rack because of the lack of stability created by jacking up against the angular underside of the steering control arm. Jack support pads commonly installed on wheel alignment racks are located below this dangerous angular portion of the control arm. In other wheel aligment racks not having such jack support pads, the jack is typically placed on an adjustable cross-beam that extends between the runways of the rack. In this type of rack, the portion of the cross-beam that supports the jack also is located below the dangerous angular portion of the steering control arm.
Thus, there is a need to provide a means for lifting the front end of a vehicle in a safe position for making wheel alignments. It is also desirable that such a lifting means be compatible with existing types of wheel alignment racks.